In this kind of toggle means according to the conventional art, a plurality of links are each previously linked with a plurality of shafts, and the links can be expanded by the pressure of a hydraulic means and the like. Thus, a preferable comressive force can be obtained. According to this kind of the toggle means an opening of the link is contacted under the high tension with the shaft to be passed through in the opening thereof. In other words, the shaft must be inserted tightly in the opening of the link, that is to say, the peripheral surface of the shaft must be contacted very exactly and tightly with the internal surface of the opening. In case the maximum pressure is applied to the toggle means by the expansion of a plurality of links, the opening of the link is contacted under the high tension with the shaft. Consequently, there is growing the danger that the opening of the link may be worn out or broken by high compression. What is the more important is that it is impossible to supply lubricating oil effectively in the opening of the link due to very tight contacting the shaft with the opening of the link. As a result, due to the shortage of lubricating oil, the opening of the link is collided tensely with the shaft, and subsequently the link or the shaft may be broken. In order to overcome such an disadvantage of the conventional art, the present invention has been achieved.